Abstract: In one implementation, a spectral microscope may comprise a substrate with a planar lens, the planar lens including a phase profile including an axial focus and an oblique focus, a light source to excite a signal of a particle among a plurality of particles, and a detector to receive light generated from the light source from the axial focus of the planar lens and a spectral color component of the excited signal of the particle from the oblique focus of the planar lens.

Abstract: An oximeter probe that takes into account tissue color (e.g., skin color or melanin content) to improve accuracy when determining oxygen saturation of tissue. Light is transmitted from a light source into tissue having melanin (e.g., eumelanin or pheomelanin). Light reflected from the tissue is received by a detector. A compensation factor is determined to account for absorption due to the melanin. The oximeter uses this compensation factor and determines a melanin-corrected oxygen saturation value.

Abstract: The invention relates to diagnosis in general and more specifically a system and a method for determining the presence of jaundice in newborn babies, also known as neonatal jaundice. A main objective of the present invention is to provide a simple system and method for determining the presence of jaundice. Particularly since most deaths due to jaundice occur in low-income countries, there is a large unmet need of simple, reliable and affordable technologies able to identify at-risk newborn. The objective is accomplished through receiving a depiction of skin from an RGB sensor, and then using either an optical diffusion model of the skin or Monte Carlo simulations to calculate the bilirubin concentration. A meta model of the optical diffusion model or Monte Carlo simulations can also be used. Colour calibration is also performed by e.g. thin-plate spline interpolation.

Abstract: A low energy particle detection device comprises alight source, multiple photodetectors positioned at different scattering angles, and a microcontroller for computing a total mass concentration of fine and ultrafine particles and a mass fraction of ultrafine particles to fine particles in an incoming air particle airflow based on the ratio of the readings from the multiple photodetectors. The optical particle detection device also can determine surface area concentration of the air particle sample and the associated lung deposited surface area (LDSA) to measure and improve estimates of air quality.

Abstract: A measurement device includes mechanical support elements (101-104) for supporting a sample well, other mechanical support elements (105-109) for supporting a measurement head (112) suitable for optical measurements, and a control system (111) configured to control the measurement head to carry out at least two optical measurements from at least two different measurement locations inside the sample well, where each measurement location is a center point of a capture range from which radiation is captured in the respective optical measurement. The final measurement result is formed from the results of the at least two optical measurements in accordance with a pre-determined rule. The use of the at least two optical measurements from different measurement locations reduces measurement variation in situations where the sample well (153) contains a piece (158) of sample carrier.

Abstract: The invention discloses a smoke detection method, which comprises the steps of: adjusting a detection period of a smoke alarm to be a rapid detection period when a smoke density is detected to meet a set density threshold; calculating a ratio of an electrical signal increment caused by a first transmitted signal to an electrical signal increment caused by a second transmitted signal; and increasing a smoke alarm threshold when smoke is judged not to be caused by a fire hazard based on the ratio. In the invention, different types of smoke can be identified and different alarm modes can be selected to solve the problem of a false alarm.

Abstract: A system and method monitor contaminants in fluid flowing in a structure, including contaminating particles that may be present in a fuel supplied through a pipe to a combustor of a gas turbine. The system includes a light source for projecting a light sheet on a cross-sectional area of the structure; an optical sensor for sensing particles passing through the light sheet; and a controller for controlling the light source and the sensor. A window can be formed in an outer wall of the structure, and the sensor disposed outside the structure to sense the passing particles via the window. The optical sensor acquires a monitoring image in which the particles passing through the light sheet are included, and the controller performs an image analysis on the acquired monitoring image and calculates whether contaminants are included in the fluid and a degree to which contaminants are included in the fluid.

Abstract: Disclosed is a sheath delivery system that uses a continuous flow of sheath fluid into a pressurized internal reservoir that substantially matches the outflow of sheath fluid through the nozzle of a flow cytometer. A substantially constant level of the sheath fluid is maintained. If the sheath fluid level falls below a desired level, or goes above a desired level, a dampened control system is used to reach the desired level. In addition, air pressure in the pressurized internal container is controlled so that an external sheath container can be removed and refilled with additional sheath fluid without stopping the sheath delivery system 100. Differences in pressure are detected by a droplet camera, which measures the droplet breakoff point to determine the pressure of the sheath fluid in the nozzle.

Abstract: There is provided a light control circuit including a detected voltage generating circuit, a reference voltage generating circuit, an error amplifier, an NMOS driver and a light source. The detected voltage generating circuit outputs a detected voltage to a first input terminal of the error amplifier. The reference voltage generating circuit outputs a reference voltage to a second input terminal of the error amplifier. The NMOS driver changes a drive current of the light source according to an output of the error amplifier.

Abstract: The present technology provides a technology of improving measurement efficiency in microparticle measurement for optically measuring a characteristic of a microparticle. For this, in the present technology, there is provided a microparticle measuring device and the like provided with a detecting unit which detects light from a microparticle sent from one of a plurality of containers containing microparticles, and an information processing unit which controls to specify a feature amount related to a detection number in a certain time section on the basis of information detected by the detecting unit, determine that the feature amount is abnormal on the basis of a predetermined threshold, and finish detection for the one container.

Abstract: Embodiments of the disclosure provide a camera system for a vehicle and a sensing method using such a camera system. The camera system includes a plurality of cameras each configured with a different camera setting. The cameras collectively keep a predetermined image space in focus. The predetermined image space includes at least one object. The camera system further includes a controller. The controller is configured to receive image data captured by the plurality of cameras of the predetermined image space, and determine depth information of the at least one object based on the image data.

Abstract: A particle detector, e.g. a smoke detector is described. In one form the detector includes a detection chamber and radiation source emitting a single beam of radiation. The detector also includes a radiation receiving system and an imaging system arranged to receive radiation from a common region of interest. Methods and systems for analysing the output of a particle detector are also disclosed.

Abstract: An air conditioner including a first filter; a second filter located downstream of the first filter; a dust amount sensor located upstream of the first filter and having a hole through which dust passes, the dust amount sensor configured to transmit, per unit of time, each of a first total, which is an amount of dust in a first size range, and a second total, which is an amount of dust in a second size range smaller than the first size range, of the dust passing through the hole; and a controller configured to output a service signal for the first filter if the accumulated value of the first total transmitted from the dust amount sensor exceeds a first set value, and output a service signal for the second filter if the accumulated value of the second total transmitted from the dust amount sensor exceeds a second set value.

Abstract: In some embodiments, a system for collecting information from a sample includes a sample stage and one or more signal detectors. The sample stage includes a heating element, and the heating element is capable of heating at least a portion of the sample stage to at least 100 Celsius. The one or more signal detectors has a detection material with a silicon nitride window positioned between the detection material and the sample stage.

Abstract: An onboard detector includes a cable including plural electric wires and a sensor module provided at an end of the cable. The sensor module includes a sensor, a housing member and a molded article. The sensor includes a sensor main body including a detecting element and plural lead wires electrically connected to the electric wires. The housing member includes a joint housing portion that houses joints of the electric wires and the lead wires. The molded article includes molding resin that is molded so as to cover at least a portion of the housing member and so as not to come into contact with the sensor main body. The joint housing portion includes a wire holding wall holding the electric wires and a sensor holding wall holding the lead wires so as to hold the sensor.

Abstract: Provided herein are an optical test platform and corresponding method of manufacturing the same. The test platform may include a shell defining a cavity for receiving a sample tube, a first aperture, and a second aperture. The first aperture and the second aperture of the shell may each be configured to optically couple the cavity with an exterior of the shell. The test platform may further include a first window and a second window embedded in the shell. The first window may seal a first aperture and the second window may seal a second aperture. The first window and second window may each permit the optical coupling of the cavity with the exterior of the shell. The first window and the second window may be optically coupled via the cavity, and the shell may prohibit optical coupling between the first window and the second window through the shell.

Abstract: Provided is an alarm device which is attached to an installation surface of an installation object and has an installation surface side facing surface facing an installation surface, the alarm device including detection means for detecting smoke included in a gas, a casing accommodating the detection means, and guide means for guiding a gas into the casing.

Abstract: The present disclosure provides for a system and method of concentrating airborne particles, specifically toward the center of one or more intake channels of PM sensors. The invention provides a simple and cost effective device that, when used in conjunction with a MEMS PM sensor or the like, can increase the sensitivity of said device by orders of magnitude. An in-line MEMS PM concentrator uses a converging optical intensity field to concentrate particulate matter along the center of a longitudinal axis of a microchannel. More specifically, the concentrator is designed to bring in ambient air containing PM through a microchannel and concentrate the PM in the center of the microchannel using a converging optical intensity field within a confocal optical cavity.

Abstract: An optical analysis device for determining particulate matter includes three light sources having different wavelengths, an apparatus for combining the three transmitted light beams on a common optical path, a measurement volume, an optical axis in the forward scattering direction defines the scattering angle 0°, a light absorption apparatus at 0° that absorbs unscattered light, and six detectors which are arranged at different specified angles which are as close as possible to 0° directly next to the light absorption apparatus, at a second scattering angle between 7° and 40°, at a third scattering angle between 41° and 70°, at a fourth scattering angle between 71° and 115°, at a fifth scattering angle between 116° and 145°, at a sixth scattering angle between 146° and 180°. A control and evaluation unit controls the light sources such that the scattered light is detected in a wavelength selective manner by the detectors.

Abstract: A device and method for measuring precipitation, in particular snowfall or hail, which has a measuring chamber for receiving a precipitation particle, at least one light source for radiating the measuring chamber with light, and at least one sensor for sensing an intensity of the light radiating through the measuring chamber. At least two measurement areas, which are arranged one below the other, are provided in the measuring chamber, and the intensity of the light radiating through each of the measurement areas can be detected separately.

Abstract: Hollow motor apparatuses and associated systems and methods for manufacturing the same are disclosed herein. In representative embodiment, a hollow motor apparatus includes a rotor assembly rotatable about a rotation axis, a stator assembly positioned adjacent to the rotor assembly and coaxially with the rotor assembly relative to the rotation axis, and a bearing assembly operably coupled to the rotor assembly. The rotor assembly has an inner portion around an opening configured to receive at least a portion of a payload. The bearing assembly is disposed outside the inner portion of the rotor assembly and is configured to maintain a position of the rotor assembly relative to the stator assembly.

Abstract: A particle analyzer is intended to accurately obtain an aspect ratio and a major axis length or a minor axis length of particles being dispersed in a dispersion medium.

Abstract: Various embodiments include methods of reducing false-particle counts in a water-based condensation particle counter (CPC). One embodiment of a method includes delivering water into one or more wicks, sensing an excess volume of water delivered to the wicks, collecting the excess volume of water into a collection reservoir, and draining the excess volume of water from the collection reservoir. Other methods and apparatuses are disclosed.

Abstract: Various embodiments include methods of reducing false-particle counts in a water-based condensation particle counter (CPC). One embodiment of a method includes delivering water into one or more wicks, sensing an excess volume of water delivered to the wicks, collecting the excess volume of water into a collection reservoir, and draining the excess volume of water from the collection reservoir. Other methods and apparatuses are disclosed.

Abstract: A method for monitoring an area includes distributing, by a detector unit, light during a first instance of time in order to characterize the area based on first data associated with the first instance of time; distributing, by the detector unit, light during at least a second instance of time in order to obtain second data; comparing a first portion of the second data to at least one of: a second portion of the second data and the first data; and based on the comparison, signaling an alarm condition by the detector unit when an evolution in the second data is detected in an amount greater than a threshold.

Abstract: A photon-counting system includes photon-counting detectors that output photon-counting signals to indicate a number of photons impinging on the photon-counting detectors. The system also includes analog-to-digital conversion circuits, which convert one of the photon-counting signals into a digital photon-counting signals, and a processor that processes the digital photon-counting signals to extract information from the photon-counting signals. The information extracted can include a photon-counting rate. An intelligent multiplexer that, based on the photon-counting rate, modifies interconnection of the photon-counting detectors and analog-to-digital conversion circuits and provides digital photon-counting signals for a selected set of the analog-to-digital converters to the processor.

Abstract: The present invention relates to a method for determining the relief of the skin surface of a subject, and hence the degree of maturation of the said skin surface. Methods for identifying active agents, raw materials and formulation are also provided.

Abstract: A metal detection apparatus (9) is tested with a test device (7) having at least one test article (79), movable through a detection zone (60). The test article is moved through the detection zone along a first transfer axis (ca) and a first input signal is measured. A first threshold (th1) is determined, where an amplitude of the first input signal exceeds the first threshold (th1). Then, an identical test article is moved through the detection zone along a further transfer axis (ta; . . . ) and a further input signal is measured and a further threshold (th2; . . . ) is determined, where an amplitude of the further input signal exceeds the further threshold (th2; . . . ). The first or further threshold (th1; th2; . . . ) is selected in the signal processing path (4) whenever the test article is moved along the related transfer axis (ca; ta; . . . ).

Abstract: A method and an apparatus for measuring a time-varying change in an amount of blood in a tissue include exciting a fluorescence agent in the blood, acquiring a time-varying light intensity signal during a pulsatile flow of the blood through the tissue volume, the pulsatile flow having a systolic and a diastolic phase resembling a conventional photoplethysmogram, and processing the acquired signal by applying a modified Beer-Lambert law to obtain the measurement of the time-varying change in the amount of blood in the tissue volume. The instantaneous molar concentration of the fluorescence agent is determined by utilizing a concentration-mediated change in a fluorescence emission spectrum of the fluorescence agent.

Abstract: A soldering device includes a detection sensor which can detect a liquid level height of molten solder inside a solder bath. It is determined whether or not a detection height which is the detected liquid level height is greater than or equal to a first set height which is arbitrarily set. In a case where the detection height is greater than or equal to the first set height, it is estimated that the amount of molten solder capable of performing a soldering work for a predetermined number or more of boards is stored in the solder bath. The amount of molten solder stored in the solder bath is estimated by multiplying a difference between a detection height which is the detected liquid level height of the molten solder and a second set height which is preset, by an area inside the solder bath in a horizontal direction.

Abstract: A water quality sensor includes a housing including a light transmissive bucket mounted in an electrical washing appliance and a light transmissive inner barrel mounted in the bucket, an actuation module mounted in the inner barrel for detecting a water quality of a washing solution in the electrical washing appliance. Thus, if the bucket is cracked during manufacturing or due to a collision, the actuation module can still be well protected by the inner barrel, so that the washing solution in the electrical washing machine does not directly flow into and contact with the actuation module to cause an accidental short circuit of the circuit substrate of the actuation module, improving the water resistance and service life of the water quality sensor.

Abstract: One variation of a method for detecting a fire includes: during a first time period: detecting an increase in ambient light intensity and detecting an increase in ambient humidity; responsive to the increase in ambient light intensity and the increase in ambient humidity, detecting a fire event; during a second time period: correlating a decrease in ambient light intensity with an increase in visual obscuration; detecting an increase in ambient air temperature; in response to a magnitude of the increase in visual obscuration remaining below a high obscuration threshold and a magnitude of the increase in ambient temperature remaining below a high temperature threshold, classifying the fire as an incipient fire; and, in response to the magnitude of the increase in visual obscuration exceeding the high obscuration threshold and the magnitude of the increase in ambient temperature exceeding the high temperature threshold, classifying the fire as a developed fire.

Abstract: An operating method of a biological detection calibration system, adapted for a biological detection device which includes a light source for emitting a light to detect a biological sample. A step is performed to detect whether a light calibration device exists on the biological detection device, wherein the light calibration device includes a carrier and a calibration sample disposed on the carrier, and the calibration sample includes a light detector. If the light calibration device exists, the intensity of the light detected by the light detector is read to determine whether the intensity of the light detected by the light detector is less than a predetermined value. If the intensity of the light detected by the light detector is less than the predetermined value, a driving voltage of the light source is enhanced, such that the intensity of the light detected by the light detector reaches the predetermined value.

Abstract: A particle characterization apparatus comprising: a light source for illuminating a sample with a light beam; a detector arranged to detect scattered light from the interaction of the light beam with the sample; and a focus tuneable lens arranged to collect the scattered light for the detector from a scattering volume and/or to direct the light beam into the sample.

Abstract: A composite fire detector (12) which senses a heat temperature, smoke concentration, and gas concentration due to fire is connected to a transmission path (16) drawn from a fire receiver (10). When a fire test operation is sensed by the fire receiver, a test mode is set to the fire detector. The fire detector performs display control over alarm indicating lights in a mutually varied manner corresponding to each alarm test when a test jig is used to conduct an alarm test by sensing of a heat temperature, an alarm test by sensing of a smoke concentration, and an alarm test by sensing of a gas concentration in a state where the test mode is set. For example, the fire detector repeats one-time blinking of the alarm indicating lights for heat sensing, two-time blinking for smoke sensing, and three-time blinking for gas sensing at intervals of a predetermined nonoperating period.

Abstract: A smoke detector includes an illuminator, a light sensor, a memory, and a microprocessor. The illuminator is configured to emit a first electromagnetic signal having a first center wavelength and a second electromagnetic signal having a second center wavelength. The light sensor is configured to generate (a) a first clean-air voltage in response to receiving the first electromagnetic signal and (b) a second clean-air voltage in response to receiving the second electromagnetic signal. The memory stores non-transitory computer-readable instructions. The microprocessor is adapted to execute the instructions to: (i) determine a first signal drift value from the first clean-air voltage and a first reference voltage, (ii) determine a second signal drift value from the second clean-air voltage and a second reference voltage, and (iii) determine the operational state from both the first signal drift value and the second signal drift value.

Abstract: Embodiments are directed to an apparatus that includes a fluidic structure and optical components. The fluidic structure includes a transparent channel through which objects in an analyte fluid can travel along respective paths during operation of the apparatus. The optical components are configured to provide measurement light to the objects traveling through the transparent channel. The fluidic structure is configured to reversibly engage with a host structure. The host structure includes a source of the measurement light and electronics to receive and process output light emanating from the objects traveling in the channel. The fluidic structure makes an air-tight seal when engaged with the host structure.

Abstract: The invention provides an open-stage near-TIRF microscope in which all of the optical components are positioned underneath the sample, allowing for physical access to, and control over the environment of, the sample. The microscope can be used to image cells expressing fluorescent voltage indicators. Since the TIRF components do not interfere with the sample, living cells can be studied using a microscope of the invention. Where a sample includes electrically active cells expressing fluorescent voltage indicators, the microscope can be used to view voltage changes in, and thus the electrical activity of, those cells.

Abstract: A transmitter includes a light source which enables changing the characteristic of light, on a time-series basis, and a controller which sets a predetermined duration for a symbol included in information to be transmitted and controls the light source to change the characteristic of the light emitted by the light source, on a time-series basis in accordance with a value of the symbol in the duration. A receiver includes a camera which generates a plurality of images each recording an image capturing range including at least a part of an area irradiated with the light from the transmitter, with a predetermined image capturing period, and a processor configured to extract a feature amount representing the characteristic of the light, from each of the plurality of images, and decode the value of the symbol from a time-series change in the feature amount.

Abstract: A method includes generating light in a light generating chamber, causing a portion of the generated light to pass through a tube having a roughened inner surface, and detecting the portion of the generated light that has passed through the tube using a photodetector. The roughened inner surface of the tube has a surface roughness sufficient to cause grazing incidences of light to be eliminated rather than to be reflected off the roughened inner surface. In one example, the method includes outputting a signal from the photodetector to a controller, with the signal corresponding to the detected portion of the generated light. The light generated in the light generating chamber can be extreme ultraviolet (EUV) light. In tests using roughened and non-roughened protection tubes, the roughened tube was found to minimize or essentially eliminate the contribution to EUV energy from grazing incidence reflections off the inner surface of the tube.

Abstract: Apparatus and associated methods relate to determining metrics of water particles in clouds by directing light pulses at a cloud and measuring a peak, a post-peak value and a high-frequency fluctuation of light signals reflected from the cloud. The light pulses include: a first pulse having circularly polarized light of a first wavelength; and a second pulse of a second wavelength. The reflected light signals include: a first reflected light signal having left-hand circular polarization of the first wavelength; a second reflected light signal having right-hand circular polarization of the first wavelength; and a third reflected light signal of the second wavelength. An extinction coefficient and a backscatter coefficient are determined based on the measured peak and post-peak slopes of the first and second reflected light signals. The measured high-frequency fluctuations of the three reflected light signals can be used to calculate cloud particle sizes.

Abstract: System and method for determining a viscoelastic modulus of a sample with the use of optical data and an average size of light-scattering particles, of such sample, that has been derived from the optical data in reliance of angular dependence of a radiant flux profile determined from laser speckles formed by the sample and, in required, on a refractive index mismatch between light-scattering particles and sample medium hosting such particles. The determination is optionally carried out by taking into account at least one of absorption coefficient and reduced scattering coefficient of the sample, which are also determined from the same optical data. Laser speckle may be formed for different combinations of polarization states of sample-illuminating light and detected light and/or different wavelengths to account for polydisperse nature of the sample.

Abstract: A device (1) is described and represented for the determination of the particle size and/or the particle shape and/or optical properties, such as transparency, of particles (2) in a particle stream (3), with a feeding device (4) for the feeding of the particles (2) to a measuring zone (5), wherein the particles (2) flow through the measuring zone (5), with at least one illuminating device (6) for illuminating the measuring zone (5), with at least two camera devices (7, 8), each of which photographs a measurement region (9, 10) of the measuring zone (5) associated with the corresponding camera device (7, 8), wherein a first camera device (7) photographs a first, preferably larger, measurement region (10) with a first, preferably lesser, magnification and a second camera device (8) photographs a second, preferably smaller, measurement region (9) with a second, preferably stronger, magnification, with an imaging optics (11) for imaging the measurement regions (9, 10), and with an evaluating device for determinin

Abstract: A molded lens assembly includes a cover and at least four molded elongated features. The cover may have a substantially planar portion and side portions extending away perpendicularly at a periphery of the substantially planar portion and defining an inner surface of the substantially planar portion. The at least four molded elongated features generally extend away from the inner surface of the substantially planar portion and are arranged such that a long axis of each of the molded elongated features is aligned with a side of a polygon having a number of sides equal to the number of molded elongated features. Each molded elongated feature generally includes a first convex lens portion at a first end and a second convex lens portion at a second end.

Abstract: A particle sensing device, which senses a particulate matter by using a light beam from a light source, is provided. The particle sensing device includes a columnar array and a light-sensing element. The columnar array is disposed at a downstream side of a traveling path of the light beam. The columnar array has a plurality of columnar objects. A gap is existed between two adjacent columnar objects. The light-sensing element is disposed opposite to the columnar array and at a downstream side of a traveling path of the light beam. Wherein, the traveling path of the light beam is parallel with a length direction of each columnar object. And, the light beam passes through the gap for arriving at the light-sensing element. The particle sensing device can sense the particulate matter satisfactorily and can be simply integrated into various electronic apparatuses.

Abstract: A waveguide, such as an optical fiber, having a front face, such as a fiber facet, is provided with a coating. The coating having one or more organic fluorine compounds. The invention also concerns a method for producing this type of waveguide by means of plasma polymerization.

Abstract: Measurement light is cast from a light-casting unit into a flow cell. The light is repeatedly reflected at an outer surface of the flow cell. A detecting unit including a connecting element and a photodetector element is provided in contact with the outer surface of the flow cell. Since the connecting element is made of a material whose refractive index is higher than that of the wall of the flow cell, the light is extracted from the flow cell at the contact position of the connecting element, to be detected by the photodetector element. A shift of the attachment position of the detecting unit along the axis of the flow cell changes the optical path length of the measurement light. A high-sensitivity absorption measurement can be performed by controlling the optical path length by merely changing the attachment position of the detecting unit, without replacing the flow cell.

Abstract: One embodiment provides a method for monitoring the quality of nanofibrillar cellulose produced in a process comprising disintegrating fibers of cellulose pulp, the method comprising measuring in real-time optically the turbidity of a dispersion containing nanofibrillar cellulose obtained from a disintegrating process, and determining the quality of said produced nanofibrillar cellulose using a correlation between the measured turbidity and said quality of the produced nanofibrillar cellulose, wherein lowered turbidity indicates increased quality of the nanofibrillar cellulose. One embodiment provides a device for monitoring the quality of nanofibrillar cellulose produced in a process comprising disintegrating fibers of cellulose pulp, arranged to carry out said method.

Abstract: An optical smoke detector includes a radiant energy source and a sensor. The source and the sensor are carried by an optical block that provides a fixed orientation therebetween and barriers therebetween. The barriers reduce noise and false alarming due to bugs, dust, water vapor, and other intrusive elements. The barriers can include V-shaped members at a selective angle relative to center lines of the source and the sensor.

Abstract: A personnel monitoring system. The personnel monitoring system includes a host node having an optical source for generating optical signals, and an optical receiver. The personnel monitoring system also includes a plurality of fiber optic sensors for converting at least one of vibrational and acoustical energy to optical intensity information, each of the fiber optic sensors having: (1) at least one length of optical fiber configured to sense at least one of vibrational and acoustical energy; (2) a reflector at an end of the at least one length of optical fiber; and (3) a field node for receiving optical signals from the host node, the field node transmitting optical signals along the at least one length of optical fiber, receiving optical signals back from the at least one length of optical fiber, and transmitting optical signals to the optical receiver of the host node.